Downdraft Device Dismisses Dust

November 4, 2019 by Kristina Panos 9 Comments

Woodworking is messy business, especially the sanding part. But even if you don’t care what happens to your shop floor, you don’t want dead tree particulate matter in your lungs. Wearing a mask or even a respirator is a good start, but a dust collection system is better. Someday, [XYZ Create] might have a shop-wide sawdust-slurper installed. In the meantime, he made a downdraft table out of scrap plywood and a plastic storage box.

The only thing he didn’t already have on hand was a port that matched his shop vacuum. We like his workaround to avoid drilling a huge hole in plastic that would certainly crack — use a hose clamp to get the OD of the port, heat up the clamp on a hot plate, and let it melt a hole into the box. Hopefully, he at least opened a window. [XYZ Create] glued four pieces of scrap plywood together for the top, and drilled all 117 holes by hand. Who needs pegboard?

Not fancy or big enough for your needs? Here’s one with a built-in filtration system.

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A New Method For Growing Watch Springs

November 2, 2019 by Sharon Lin 26 Comments

Scientists at the Swiss Federal Laboratories for Materials Science and Technology (Empa) recently developed a new technique for growing watch springs to tiny specifications. As it turns out, the creation of watch springs is ripe with opportunity for new materials research.

The technique involves using photo-etching and electrochemical deposition into cold, aqueous solutions. Compared to drawing and winding Nivarox wires, this is a fairly unconventional method for manufacturing. For as long as watchmaking has been around, creating the balance springs has been one of the most difficult parts of the job. The wires must be drawn to a thickness in the hundredths of millimeters and wound and tempered to the exact hardness, ductility, and elasticity while compensating for environmental factors. Many substances change their properties during fabrication, so the Empa team decided to look to pure materials research as a way to find a means for fabricating balance springs that would remain stable.

They took silicon wafers (the same kind used for solar panels and computer chips), covered them in gold and a thin layer of light sensitive paint, and etched the shape of a spring into the wafer. The wafer was then dipped into a galvanic bath containing a salt solution from a metallic alloy — the spring acts as a cathode so that when an electric current passes through the bath, metal is deposited at the base of the spring. Once the spring is built up, it is dissolved from the mold and examined. After a bit of smoothing, the final spring is washed and sent to a lab for prototype production.

The electroplated springs are currently on display at the Laboratory for Mechanics of Materials and Nanostructures at the Empa campus in Thun, Switzerland. In the meantime, the first pilot tests are being wrapped up, and the team is beginning to work with Swiss watchmakers to see if their springs can hold up inside watch mechanisms.

[Thanks to Qes for the tip!]

Be Anyone Or Anything With Facial Projection Mask

October 31, 2019 by Dan Maloney 18 Comments

In the market for a low-poly change to your look? Hate the idea of showing up for a costume party only to find out someone is wearing the same mask as you? Then this face changing front-projection mask may be just the thing for you.

To be honest, we’re not sure just how much [Sean Hodgins]’ latest project has to do with cosplay. He seems to be making a subtle commentary about dealing with life in the surveillance state, even though this is probably not a strategy for thwarting facial-recognition cameras. [Ed Note: Or maybe it’s just Halloween?]

The build consists of a Raspberry Pi and a pico projector of the kind we’ve seen before. These are mated together via a custom PCB and live inside a small enclosure that’s attached to the end of a longish boom. The boom attaches to the chin of 3D-printed mask, which in turn is connected to the suspension system of a welding helmet. Powered by a battery pack and controlled by a smartphone app, the projector throws whatever you want onto the mask – videos, effects, even images of other people. Even with some Photoshop tweaks to account for keystone distortion from the low angle of projection, there’s enough distortion that the effect is more artistic than masquerade. But honestly, having your face suddenly burst into flames is pretty cool. We just wonder what visibility is like for the wearer with a bright LED blasting into your eyes.

As a bonus, [Sean] has worked this build into a virtual treasure hunt. Check out 13thkey.com and see what you can make from the minimal clues there.

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Syringes Become Rockets In This Flying Build

October 30, 2019 by Lewin Day 3 Comments

Syringes have all kinds of useful applications in the workshop, from injecting fluids to helping pick up tiny components. There’s always room for a bit of levity however, and [Tom Stanton] decided to have a play with some syringe rocket builds.

The basic idea involves blocking the end of a syringe, and then pull the plunger to create a vacuum in the tube. When released, the plunger will rush forward from the atmospheric pressure counteracting the vacuum, hitting the end of the tube and launching the syringe forward.

[Tom]’s initial attempts with small syringes were fun, but larger builds struggled with breakages, sealing issues, and excessive weight. Some more luck was had with a vacuum cannon build, which was able to launch a projectile to a decent height, albeit without a lot of stability. [Tom] wrapped things up by designing a small 3D printed launcher that fits 10mm syringes and lets you shoot them around the workshop with abandon.

It’s fun to see the concept explored in detail, with [Tom] doing a great job of explaining the basic physics behind the phenomenon. If you’re hungry for more, consider using syringes as basic hydraulic actuators for model builds. Video after the break.

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Simple Seismic Sensor Makes Earthquake Detection Personal

October 28, 2019 by Dan Maloney 6 Comments

When an earthquake strikes, it’s usually hard to miss. At least that’s the case with the big ones; the dozens or hundreds of little quakes that go largely unnoticed every day are interesting too, and make sense to track. That’s usually left to the professionals, with racks of sensitive equipment and a far-flung network of seismic sensors. That doesn’t mean you can’t keep track of doings below your feet yourself, with something like this DIY seismograph.

Technically, what [Alex] built is better called a “seismic detector” since it’s not calibrated in any way. It’s just a simple sensor for detecting ground vibrations, whether they be due to passing trucks or The Big One. [Alex] lives in California, wedged between the Hayward, Calaveras, and San Andreas faults in San Jose, so there is plenty of opportunity for testing his device. The business end is a simple pendulum sensor, with a heavy metal bob hanging from a long wire inside a length of plastic pipe. Positioned close to the bob is a copper plate; the bob and the plate form an air-dielectric variable capacitor that controls the frequency of a simple 555 oscillator. The frequency is measured by a PIC microcontroller and sent to a Raspberry Pi, which displays the data on a graph. You can check in on real-time seismic activity in San Jose using the link above, or check out historical quakes, like the 7.1 magnitude Ridgecrest quake in July. [Alex]’s sensor is sensitive enough to pick up recent quakes in Peru, Fiji, and Nevada, and he even has some examples of visualizing the Earth’s core using data from the sensor. How cool is that?

We’ve seen other seismic detectors before, like this piezo-based device, or even one made from toilet parts. We like the simplicity of the capacitive sensor [Alex] used, though.

Horse Racing Game Hits Trifecta Of Fun, Skill, And Competition

October 26, 2019 by Kristina Panos 4 Comments

Out in the neon-painted desert of Las Vegas, if you know where to look, you can find an old, 1980s electromechanical horse racing game called Sigma Derby. In this group game, you and several drunk strangers sit around a machine the size of a pool table and bet on tiny horses at 25 cents a throw. There is no skill involved, it’s all chance. This is not that game.

[Alex Kov]’s electromechanical horse racing game is a unicorn compared to Sigma Derby, or at least a zebra. This game takes patience, skill, and cunning. And unlike Sigma Derby, you can easily replicate it at home with a few shakes of the old junk bin. You just need a couple of motors, transistors, electrolytic caps, and some passives.

The idea is simple — advance horse, be first, win prizes — but it’s not that easy. While the switch is unpressed, the circuit charges up a capacitor. Press it and the horse noses forward, draining the cap. There is never enough chooch in the cap to reach the finish line, so the real game is in building up more juice than the other guy, and then staying ahead or overtaking him with the next spurt. Place your bets and catch the action after the break.

A scoreboard would be a great addition to this game. If you want to keep it electromechanical, we have some tote board inspiration for you.

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Laser Toy Keeps Cats Entertained

October 26, 2019 by Lewin Day 13 Comments

Cats are among the most popular domesticated creatures, and their penchant for chasing laser pointers is well known. With a pair of felines of his own to look after, [Tobi] set about making a device to help keep them entertained.

The aim of the device is to automate the motion of a laser pointer to make playing with the cats a hands-free operation. A pan-tilt servo mechanism has a low-power red laser pointer fitted, and the assembly is hooked up to a NodeMCU microcontroller. Based on the ESP8266, it allows the system to be controlled remotely over WiFi. Various sweeps can be automatically commanded from a smartphone, or the servo position can be controlled manually.

Test footage confirms that [Tobi’s] pets do indeed find the device to be worthy prey. It’s a popular build for cat lovers, and readily achievable with off-the-shelf parts. If you’ve built your own hardware to keep these proud hunters out of trouble, be sure to hit up the tip line.